MONTGOMERY, Ala. - A federal appeals court Thursday ordered that former Alabama Gov. Don Siegelman be released from prison on bond while his bribery conviction appeal is heard.

Siegelman was imprisoned immediately after he was sentenced in 2007 to 88 months for exchanging a seat on the state hospital licensing board for a contribution to an education lottery campaign. His lawyers argued that he should not have been incarcerated while he appealed his conviction, The New York Times reported.

In Thursday's ruling, the U.S. Court of Appeals for the 11th Circuit in Atlanta found that Siegelman's appeal had raised "substantial questions."

Earlier Thursday, Democratic members of the House Judiciary Committee asked the U.S. Justice Department to permit Siegelman to travel to Washington to testify about his prosecution, which Siegelman and others have claimed was motivated by partisan politics.

Fifty-four former state attorneys general, including some Republicans, asked the U.S. Congress in September to investigate Siegelman's conviction. The former prosecutors said the case "may have had sufficient irregularities as to call into question the basic fairness … of our system of justice."

A Republican "opposition researcher" told CBS last month former White House aide Karl Rove asked her in 2001 to get compromising pictures of Siegelman, a Democrat.